1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to a communication between sub-networks, and more particularly, to discovering a component in a sub-network.
2. Description of Related Art
Generally, when two components which are different from each other communicate, a recognition process is previously required. For a previous recognition process, records of previous communications should physically exist or information on components to communicate should be acquired via other paths.
An address and a port number of a corresponding device are required so that communications among components using an Internet protocol (IP) address system are performed in the Internet. IP addresses and identifiers of all components, directly connected to the Internet, are registered in a domain name system (DNS), and thus another component may ascertain the addresses from the identifiers with respect to the components. Also, port numbers are standardized so that a predetermined port may receive from only other ports having the same port number.
In this instance, the IP addresses indicate unique identification addresses which are provided to all networks connected to the Internet, and computers, connected to the networks.
However, disadvantages of communications among components included in different sub-networks are as follows.
First, as an example, when a component has an IP address allocated as in an ad hoc network, the component does not always have a same IP address. Accordingly, components of different sub-networks may not communicate. Specifically, when building an ad hoc network, IP addresses may not be ascertained via DNS.
Second, in a related art, a separate action by routers to process multicast packets is required for discovering components in sub-networks, which causes loss of time and cost.
Accordingly, a more effective method and apparatus for discovering a component in at least one sub-network is needed.